docstr: Returns the features known by this model
docstr_tok: ["Returns","the","features","known","by","this","model"]
code: def get_known_feats(self):
      """
      Returns the features known by this model
      """
      values = {
          k: v.keys() - VOCAB_PREFIX
          for k, v in self.vocab["feats"]._unit2id.items()
      }
      return values
  
file_path: stanza/stanza/pipeline/pos_processor.py
imports: import torch
  from stanza.models.common import doc
  from stanza.models.common.utils import unsort
  from stanza.models.common.vocab import VOCAB_PREFIX, CompositeVocab
  from stanza.models.pos.data import Dataset
  from stanza.models.pos.trainer import Trainer
  from stanza.pipeline._constants import *
  from stanza.pipeline.processor import UDProcessor, register_processor
  from stanza.utils.get_tqdm import get_tqdm
label_desc: Use image node_id 6 for calling the POSProcessor obj's underlying member method code with example usage: obj.get_known_feats() and returns: values